(1) Field of the Invention
The present invention pertains to a nozzle assembly for a hand held and hand operated liquid sprayer typically called a trigger sprayer. In particular, the present invention pertains to a nozzle assembly for a trigger sprayer employed in dispensing viscous liquids. The nozzle assembly produces enhanced dispersion and uniformity in the spray pattern of the viscous liquid dispensed by the trigger sprayer.
(2) Description of Related Art
Hand held and hand operated liquid sprayers commonly known as trigger sprayers are well known in the liquid sprayer art. Trigger sprayers are commonly used to dispense household cleaning or cooking liquids in a stream or spray pattern of the liquid. A trigger sprayer is typically connected to a plastic bottle containing the liquid dispensed by the trigger sprayer.
A typical trigger sprayer is comprised of a sprayer housing that is connected to a neck of the bottle by either a threaded connection or a bayonet-type connection.
The sprayer housing is formed with a pump chamber, a liquid discharge passage communicating with the pump chamber and a liquid supply passage communicating with the pump chamber.
A piston is mounted in the pump chamber for reciprocating movements of the piston between charge and discharge positions. A spring is usually provided on the sprayer housing for biasing the piston toward its charge position.
A trigger is mounted on the sprayer housing by a pivot connection at one end of the trigger. The trigger is also connected to the pump piston. Repeating the sequence of manually squeezing the trigger toward the sprayer housing against the bias of the pump spring and then releasing the trigger, oscillates the trigger about its pivot connection and reciprocates the pump piston between its charge and discharge positions relative to the pump chamber.
A pair of check valves or one way valves are positioned in the sprayer housing, one between the pump chamber and the liquid discharge passage and one between the pump chamber and the liquid supply passage. The liquid supply passage includes a dip tube that extends from the sprayer housing into the interior of the bottle, communicating the liquid contained in the bottle through one of the check valves to the pump chamber.
A nozzle assembly having a discharge orifice is assembled to the liquid discharge passage. The liquid discharge passage usually contains a liquid spinner assembly. The spinner assembly has a liquid spinner head at one end adjacent the nozzle orifice and the second of the check valves at its opposite end. The spinner assembly check valve controls the liquid flow from the pump chamber to the liquid discharge passage and prevents the reverse flow.
From the manual oscillating movement of the trigger that reciprocates the pump piston in the pump chamber, the liquid is drawn from the bottle through the dip tube to the pump chamber. The liquid is then pumped from the pump chamber through the liquid discharge passage and through the liquid spinner and discharge orifice and is dispensed from the trigger sprayer in a conical spray pattern.
The typical trigger sprayer described above is well suited for dispensing liquids having a viscosity similar to that of water, for example various types of cleaning liquids. However, when the sprayers are employed in dispensing more viscous liquids like cooking oil, problems are encountered.
With the limited dimensions of the swirl chamber at the head of the spinner assembly and the limited size of the nozzle orifice, an adequate spin cannot be produced in the more viscous liquids dispensed through the typical trigger sprayer to produce an acceptable discharge pattern of the liquid sprayed from the sprayer. Other types of sprayer nozzle assemblies have been developed for more viscous liquids. These other types of sprayer nozzle assemblies do not include a spinner assembly with a swirl chamber that spins the liquid prior to its discharge from the nozzle orifice. Instead, viscous liquid sprayers typically employ a plurality of angled discharge orifices, often two orifices, that direct streams of the viscous liquid discharged from the trigger sprayer at an angle toward each other. The streams of the liquid impact with each other and are dispersed in a spray pattern. However, because the impacting streams of viscous liquid and the spray pattern they produce are outside the discharge orifices of the sprayer nozzle, the sprayer nozzle has no control over the spray pattern produced and the spray pattern of the viscous liquid is often non-uniform.
The shortcomings of the prior art high viscosity liquid trigger sprayer are overcome by the sprayer nozzle assembly of the present invention which produces a more uniformly dispersed spray pattern of viscous liquids discharged by the nozzle assembly. The trigger sprayer with which the nozzle assembly of the invention is used is formed in the typical configuration including a pump chamber, a liquid discharge passage communicating with the pump chamber, and a liquid supply passage communicating with the pump chamber. A dip tube is assembled to the liquid supply passage and extends into the interior of the bottle when the trigger sprayer is attached to the bottle. The pump piston is mounted in the pump chamber for reciprocating movement of the piston. The trigger is mounted on the trigger sprayer for pivoting movement relative to the sprayer. The trigger is also connected to the pump piston to cause the pump piston to reciprocate between its charge and discharge positions in the pump chamber in response to manual manipulation of the trigger. The trigger sprayer also contains a pair of check valves, one controlling the flow from the dip tube to the pump chamber and preventing the reverse flow. The high viscosity liquid sprayer nozzle assembly of the invention is designed to be used with many types of manual hand held and operated sprayers having this typical construction.
The nozzle assembly of the invention is basically comprised of a nozzle housing containing a flow control member, where the nozzle housing is constructed to be assembled to the liquid discharge passage of most constructions of trigger sprayers. In the preferred embodiment, the nozzle housing and flow control member are both constructed of plastic.
The nozzle housing of the invention has a liquid conduit having a length with opposite upstream and downstream ends. The liquid conduit is dimensioned so that it can be easily attached to the liquid discharge passage of a typical trigger sprayer. The conduit contains a liquid passage having opposite upstream and downstream ends. When assembled to the trigger sprayer, the upstream end of the liquid passage communicates with the liquid discharge passage of the trigger sprayer.
The nozzle housing also has an orifice wall at the downstream end of the liquid conduit. An interior surface of the orifice wall that faces the conduit liquid passage has an axially recessed cavity at its center. A discharge orifice passes through the orifice wall at the center of the cavity. The discharge orifice has a cross-section area with an oblong, preferably rectangular shape.
The interior surface of the orifice wall is conical. A plurality of radial slots are provided in the orifice wall conical surface and extend between the conduit interior surface and the orifice wall cavity, defining a plurality of liquid flow channels that are circumferentially arranged around the recessed cavity.
The flow control member has an axial length with opposite upstream and downstream ends and is positioned in the liquid conduit of the nozzle housing. The flow control member has an elongate stem extending along its length with a flow control head at the downstream end and a valve element at the upstream end of the member. The valve element is designed to seat over an inlet opening to the liquid discharge passage of the trigger sprayer with which the nozzle assembly of the invention is used. In the preferred embodiment, the valve element is a diaphragm or disk valve, although other types of valves may be employed. The flow control head has a conical surface that projects to an apex at the extreme downstream end of the flow control member. With the flow control member positioned in the liquid conduit of the nozzle housing, the conical surface of the head engages against the conical surface of the orifice wall and covers over portions of the plurality of liquid flow channels formed by the slots in the orifice wall. The apex of the flow control head is positioned in the recessed cavity in the orifice wall and is centered relative to the orifice.
In operation of the trigger sprayer employing the nozzle assembly of the invention, viscous liquid pumped from the pump chamber of the sprayer passes through the liquid discharge passage of the trigger sprayer and past the valve element of the flow control member into the liquid conduit of the nozzle housing. The valve element functions to prevent the reverse flow of liquid from the liquid conduit back to the pump chamber. The liquid is pumped through the liquid conduit to the flow control head at the downstream end of the flow control member. The periphery of the flow control head directs the flow of liquid around the head and the conical surface of the flow control head directs the flow of liquid through the plurality of liquid flow channels formed by the radial slots in the orifice wall. Thus, the flow control head and the plurality of liquid flow channels formed by the slots initially break up the flow of viscous liquid into several streams spacially arranged around the orifice and moving toward the orifice. These several separate streams are further directed by the conical surface of the flow control head and the pluralities of liquid flow channels past the apex of the flow control head to a position where the pluralities of streams impact or collide with each other. The position of the point of collision of the plurality of streams is inside the recessed cavity in the orifice wall and at the center of the entrance to the orifice in the orifice wall. The dispersion of the plurality of separate streams of liquid colliding with each other at the entrance of the orifice is shaped by the oblong configuration of the orifice as the liquid dispersed by the collision of the plurality of streams passes through the orifice. The oblong or rectangular configuration of the orifice forms the dispersion pattern of the liquid into a narrow fan spray pattern oriented uprightly or vertically relative to the trigger sprayer held in the hand of the user.
By the operation of the novel construction of the liquid spray nozzle assembly of the invention described above, the nozzle assembly disperses viscous liquid in a uniform fan sprayed pattern that is easily employed by a user of the nozzle assembly of the invention to direct the spray of viscous fluid where desired.